1. Field of Invention
The present invention generally relates to a circuit and operating method for an integrated interface of a PDA and a wireless communication system, and more particularly, to a circuit, operating method for executing turn-on-device, power-saving, power-shortage determining, and power-charging for the integrated interface of a PDA and a wireless communication system.
2. Description of Related Art
In line with personal computer capability enhancement, the demands of portable computers increase accordingly and their functions are getting more and more mature. In the beginning, portable computer meant a lighter weight desktop computer that had to use household power supply. However, along with the development of LCD and the long-term battery, the notebook started to be accepted and used widely. The weight of a general notebook is about 2.5 kg to 3.5 kg. Therefore, the notebook indeed provides a perfect portability while keeping the complete functionality of a personal computer.
Since the notebook has acquired excellent performance in the market, many people have aggressively dedicated themselves to the development of a smaller computer. However, due to the limitation of display size and suitable input equipment, the development of the smaller computer had limited improvement. Nevertheless, finally there has been one smaller computer to breakthrough the difficulties mentioned above and be well accepted in the market. This is a computer that uses few buttons and a touch screen as input equipment, generally called the Personal Digital Assistant (PDA).
With PDA's high portability, plus the Optical Character Recognition (OCR) software, there is no much difference between a PDA and a general notebook in the convenience level of data input anymore. Therefore, the PDA is getting more and more popular in the market. The most common purpose of the general PDA is to provide the related information for daily living, such as calendar, railroad/bus time table, telephone numbers, and even domestic maps, etc. The general reason why a user uses a PDA is for its excellent portability, with which a user can get the information mentioned above to use a telephone at any time, any place. In order to contact with others at any time and any place, or to acquire the most updated and suitable information, a different sort of the wireless communication systems such as the Global System for Mobile (GSM) system or the General Packet Radio Service (GPRS) system are used to communicate with others, or through these wireless communication systems connecting to the Internet to acquire the most updated information. Either one of the above is a wonderful option.
However, PDA and all other wireless communication systems are sold independently in the current market. Therefore, besides purchasing a PDA and wireless communication systems, in order to connect to the Internet and acquire information easily, it is also necessary to purchase an appropriate network interface or use a more expensive infrared communication device to have mutual information exchange between a PDA and a wireless communication system. Therefore, users not only have to consider the compatibility between different products when they are purchased, but also have to carry all kinds of equipment for providing interfaces, which is really troublesome.